Static pressure tank, film stretching apparatus and method for blowing a gas flow against a surface to be treated

Abstract

The present disclosure provides a static pressure box and a film stretching device, the static pressure box is used for blowing the airflow introduced from the fan chamber to the surface to be processed, comprising a connecting body and a pipe body, the pipe body extends along the axial direction, the opening direction of the air outlet on the section is tangent to or forms an angle with the outer surface profile of the wall of the pipe body at the air outlet, so that the airflow blown from the air outlet flows stably along a trajectory on the section adhering to the outer surface of the pipe body wall, and mixes the ambient gas around the trajectory to blow to the surface to be processed. According to the present disclosure, the airflow blown from the air outlet can mix the ambient gas around the trajectory, thereby improving the total flow of the airflow blown to the surface to be processed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of film processing, in particular to a static pressure box, a film stretching device and a method of blowing airflow to a surface to be processed. BACKGROUND

[0002] The static pressure box is often used in a film bidirectional stretching device. The film is conveyed under the static pressure box. Hot or cold airflow generated in the fan chamber flows into the static pressure box through the air valve. After the hot or cold airflow is combed by the air guide structure in the static pressure box, the airflow flows out of the air outlet of the static pressure box and blows to the surface of the film. The hot airflow promotes the film to be heated, so as to facilitate the stretching plastic deformation of the film. Or the cold airflow promotes the film to be cooled, so as to make the film be cooled and shaped after being stretched.

[0003] The air outlet of the prior art is often arranged on the bottom surface of the static pressure box. The hot airflow flowing out of the air outlet directly blows to the surface of the film. In actual application occasions, with the increase of the width of the device, the flow rate is higher and higher, and the space required by the corresponding filtering and purifying structure is also larger and larger, which is difficult to be arranged in the device, so that the airflow flow rate blown out of the air outlet of the static pressure box cannot meet the requirements. On the other hand, the temperature of the airflow blown out of the static pressure box often needs to be controlled to be moderately reduced, so that the temperature of the airflow blown to the surface of the film matches the requirements. The airflow flow rate blown out of the air outlet of the static pressure box of the prior art cannot meet the requirements of large-size films, and the temperature drop of the airflow blown out of the air outlet to the surface of the film cannot be accurately controlled. SUMMARY

[0004] The present application provides a static pressure box and a film stretching device.

[0005] Specifically, the present application is realized by the following technical solutions:

[0006] In a first aspect, the present application provides a static pressure box for blowing airflow introduced from a fan chamber to a surface to be processed, comprising:

[0007] A pipe body extends along an axis direction in the same cross section;

[0008] A connecting body is used to connect the pipe body to the fan chamber in a dividable manner around the axis;

[0009] Wherein, an air outlet extending along the axis direction is formed on the wall of the pipe body. The opening direction of the air outlet on the cross section is tangent to or forms an angle with the outer surface profile of the wall of the pipe body at the air outlet, so as to adapt to the airflow blown out of the air outlet to flow stably along a track on the cross section adhering to the outer surface of the pipe body wall, and mix the ambient gas around the track to blow to the surface to be processed.

[0010] In some embodiments, the opening direction of the air outlet on the cross section is directed away from the surface to be treated.

[0011] In some embodiments, the number of the pipe bodies is two, the two pipe bodies extend in the same direction and are arranged side by side, and the air outlet positions of the two pipe bodies are symmetrically opposite to each other.

[0012] In some embodiments, the number of the pipe bodies is two, the two pipe bodies extend in the same direction and are arranged side by side, and the air outlet positions of the two pipe bodies are asymmetrically arranged.

[0013] In some embodiments, the cross section of the pipe body is a central symmetric shape relative to the axis.

[0014] In some embodiments, the cross section of the pipe body is a polygon.

[0015] In some embodiments, the number of the pipe bodies is two, and the pipe bodies are connected by a gear or a connecting rod mechanism, so that the two pipe bodies can rotate synchronously when adjusting the angle of the air outlet.

[0016] In some embodiments, the number of the pipe bodies is two, the two pipe bodies extend in the same direction and are arranged side by side, one end of the two pipe bodies is connected to the connecting body, and the other end of the two pipe bodies is connected to each other by a connecting rod, and the other end of each pipe body is connected to the connecting rod by a pin shaft.

[0017] In a second aspect, the embodiments of the present application provide a film stretching device, comprising:

[0018] A fan chamber for generating airflow;

[0019] A conveying mechanism for conveying a film;

[0020] The static pressure tank of the first aspect is used to blow the airflow introduced from the fan chamber to the surface of the film conveyed by the conveying mechanism.

[0021] In a third aspect, the embodiments of the present application provide a method for blowing airflow to a surface to be treated, using the static pressure tank of the first aspect, comprising:

[0022] Pre-set the target flow of the airflow blown to the film surface;

[0023] According to the target flow and the pipe body structure size, adjust the initial flow rate of the airflow blown out of the air outlet and the track distance of the stable flow adhering to the outer surface of the pipe body wall, so that the proportion of the environmental airflow in the target flow is maximized, the initial flow rate of the air outlet is reduced, and the purpose of amplifying the flow is achieved, wherein the index angle of the pipe body is adjusted around the axis to achieve the purpose of adjusting the track distance of the stable flow adhering to the outer surface of the pipe body wall.

[0024] According to various embodiments of the present disclosure, by setting the air outlet as the opening direction on the cross section being tangent to or at an angle with the outer surface profile of the wall where the pipe body is located at the air outlet, the airflow blown out of the air outlet can stably flow along a trajectory under the "wall attachment effect" and mix with the ambient air around the trajectory during the flow along the trajectory. After the mixing, the airflow blows away from the pipe wall to the surface to be treated. Since the airflow blown to the surface to be treated includes the original airflow flow rate blown out of the air outlet and the ambient air flow rate around the trajectory, the total airflow flow rate blown to the surface to be treated is increased. In addition, since the ambient air around the trajectory has a relatively lower temperature, the airflow mixing process reduces the temperature carried by the original airflow blown out of the air outlet, so that the trajectory distance of the airflow stably flowing along the pipe wall can be controlled by controlling the airflow flow rate blown out of the air outlet, and the temperature drop of the airflow blown to the surface to be treated can be accurately controlled.

[0025] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0027] Figure 1 is a schematic view of a first perspective of a static pressure tank in the first embodiment of the present disclosure;

[0028] Figure 2 is a schematic view of a second perspective of a static pressure tank in the first embodiment of the present disclosure;

[0029] Figure 3 is a schematic view of a first working state of a static pressure tank in the first embodiment of the present disclosure;

[0030] Figure 4 is a schematic view of a second working state of a static pressure tank in the first embodiment of the present disclosure;

[0031] Figure 5 is a schematic view of a third working state of a static pressure tank in the first embodiment of the present disclosure;

[0032] Figure 6 is a schematic view of a static pressure tank in the second embodiment of the present disclosure;

[0033] Figure 7 is a schematic view of a first working state of a static pressure tank in the second embodiment of the present disclosure;

[0034] Figure 8 is a schematic view of a second working state of a static pressure tank in the second embodiment of the present disclosure;

[0035] Figure 9 is a schematic diagram of a static pressure tank in a third embodiment of the present disclosure;

[0036] Figure 10 is a flow field simulation diagram of a static pressure tank outlet blowing 100 Pa air flow in a second embodiment of the present disclosure;

[0037] Figure 11 is a flow field simulation diagram of a static pressure tank outlet blowing 500 Pa air flow in a second embodiment of the present disclosure;

[0038] Figure 12 is a flow field simulation diagram of a static pressure tank outlet blowing 1000 Pa air flow in a second embodiment of the present disclosure;

[0039] Figure 13 is a thermal field simulation diagram of a static pressure tank in a second embodiment of the present disclosure;

[0040] Figure 14 is a flow field diagram of a static pressure tank in a second embodiment of the present disclosure.

[0041] Reference Signs:

[0042] 10: connecting body; 20: pipe body; 21: outlet; 30: connecting rod. DETAILED DESCRIPTION

[0043] The present disclosure will now be discussed with reference to several embodiments. It should be appreciated that these embodiments are discussed only to better illustrate the present disclosure and thus enable its best utilization, and are not intended to limit the scope of the present disclosure in any way.

[0044] As used herein, the term "includes" and its variants are to be read to be synonymous with "comprises" and its variants. The term "based on" is to be interpreted as "based, at least in part, on." The terms "embodiment" and "one embodiment" are to be interpreted as "at least one embodiment." The term "another embodiment" is to be interpreted as "at least one additional embodiment." The terms "first," "second," etc. can refer to different or identical objects. Other explicitly and implicitly recited definitions can also be found below.

[0045] In the following description, some specific numerical values or numerical value ranges can be involved. It should be understood that these numerical values and numerical value ranges are merely exemplary, which can be beneficial to put the idea of the present disclosure into practice. However, the description of these examples is not intended to limit the scope of the present disclosure in any way. According to specific application scenarios and requirements, these numerical values or numerical value ranges can be set otherwise.

[0046] As described above, in the prior art, since the static pressure box extends along the axis o direction, the air outlet also extends along the axis o direction to cover the film size, the air flow pumped by the fan chamber is low at the air outlet of each cross section of the pipe body, and since the final air volume is completely provided by the fan chamber, the required air flow of the film surface cannot be met. The static pressure box, the film stretching device and the method of blowing air flow to the film surface provided by the embodiments of the present disclosure at least partially solve the above problems. The structure and working principle of the static pressure box and the film stretching device according to the example embodiments of the present disclosure will be described below with reference to Figures 1 to 12 As shown in Figures 1-2 Generally, the static pressure box described herein includes a connecting body 10, a pipe body 20 and a connecting rod 30, wherein the connecting body 10 is used to connect the fan chamber and the pipe body 20, so that the high-pressure air flow generated by the fan chamber is introduced into the pipe body 20 through the connecting body 10, the pipe body 20 is used to blow out the introduced air flow through the air outlet 21, and the connecting rod 30 is used to fix and support the pipe body 20. In actual use, the air flow blown out from the air outlet 21 of the pipe body 20 is generally used to blow to the film surface, so as to heat treat the film surface.

[0047] It should be noted that the static pressure box of the embodiments of the present disclosure is not limited to the application field, for example, in addition to being applicable to the heating or cooling of the film surface in the stretching process, it can also be used for the heating or cooling of the workpiece surface in the coating process, the heating or cooling of the workpiece surface in the plating process, etc. In order to clearly understand the technical solutions of the embodiments of the present disclosure, the static pressure box in the film stretching process will be described in detail below. Before the film is stretched, hot air flow is blown to the film surface through the static pressure box to heat the film, so as to plastically deform the film, and the film can also be heat set, recrystallized and stress relieved. After the film is stretched, cold air flow (relative to hot air flow) is blown to the film surface through the static pressure box to cool the film, so as to keep the deformation of the film after stretching. The embodiments of the present disclosure use the "coanda effect" to make the air flow blown out from the air outlet flow along the outer surface of the pipe body wall for a certain trajectory, and then blow to the film surface together with the ambient gas mixed along the trajectory, thereby increasing the air flow.

[0048] In one embodiment, the pipe body 20 is generally tubular, the pipe body 20 defines an axis o, and the pipe body 20 extends along the axis o direction. In order to ensure that the air flow blown out from the air outlet 21 along the extension direction is uniform in flow rate and temperature, the pipe body 20 is provided to extend in an equal cross section, and the cross section shape is symmetric about the axis o. For example, the cross section shape can be circular as shown in Figures 3-5 , or can be a regular hexagon as shown in Figures 7-8 , or can be a regular pentagon, or can be a general polygon, or can be an ellipse.

[0049] In one embodiment, the air outlet 21 is formed on the wall of the pipe body 20 and extends along the axis o. For example, the air outlet 21 may be provided along the entire length from one end of the pipe body 20 to the other end, or it may be provided along the entire length of the wall of the pipe body 20, or it may be formed in multiple segments on the wall of the pipe body 20 at intervals.

[0050] The working principle of the first embodiment of this disclosure is described below, such as... Figures 3-5 As shown, the tube 20 has a circular cross-section. The film is conveyed by the conveying mechanism and passes under the tube 20. At this time, airflow needs to be blown onto the surface of the film under the tube 20 to heat or cool the film. In the first working state, as... Figure 3 As shown, the air outlet 21 is located on the same horizontal plane as the axis o on the wall of the pipe body 20, and the air outlet 21 faces upward. In this embodiment, the static pressure box includes a pair of pipe bodies 20 arranged side by side. Those skilled in the art will understand that the static pressure box may include only one pipe body 20, or it may include multiple pipe bodies 20 arranged side by side. In this embodiment, the air outlet 21 of the pair of pipe bodies 20 is located on the pipe body 20 walls on the sides of the pair of pipe bodies 20 that are close to each other.

[0051] by Figure 3 The following example illustrates the working principle of the airflow. The airflow blown out from the outlet 21 (arrow F1 in the figure indicates the original airflow direction) adheres closely to the wall of the tube 20 under the effect of the wall adhesion and flows along the outer surface contour of the tube 20 until the airflow velocity gradually decreases and it detaches from the outer surface of the tube 20 and blows towards the film surface. During the process of the airflow adhering to the outer surface of the tube 20, it can mix with the surrounding airflow (the ambient airflow in the space between a pair of tubes), causing the ambient airflow to flow together (arrow F2 in the figure indicates the ambient airflow direction), thereby increasing the flow rate of the mixed airflow. In some cases, because the temperature of the ambient airflow is lower than that of the original airflow blown out from the outlet, the temperature of the mixed airflow is also reduced.

[0052] To ensure that the airflow blowing from the outlet can stably flow along the outer surface of the pipe wall under the "wall adhesion effect" for a certain distance, the embodiment of this disclosure sets the opening direction of the outlet on the pipe cross-section to be tangent to or at an angle to the outer surface contour of the wall at the outlet. This allows the airflow to advance along the wall after being blown out of the outlet, forming a continuous air curtain within a certain distance. When the wall bends away from the airflow direction, the space between the wall and the airflow generates a relatively low pressure due to the lack of free gas filling it. The opposite side remains at normal pressure because it is connected to the atmosphere. Therefore, the pressure difference between the two sides forces the airflow to turn in the direction of the wall bend. If the wall bend angle is appropriate, the airflow can flow along the bent wall for a certain distance, thereby achieving a stable flow along the outer surface of the pipe wall in the embodiment of this disclosure.

[0053] When the air flow runs for a period of time, due to the air viscosity factor, the air flow itself flow rate decreases, the ambient air flow rate increases, and the boundary between the air flow and the ambient air gradually blurs. When the wall surface bends again, it cannot form enough pressure difference to turn with it, and it separates from the wall surface. In this process, due to the high dynamic pressure and low static pressure of the air flow itself, an ejector flow field is formed, which drives the mixed air flow together to blow to the film surface.

[0054] In the process of mixing the ambient air flow, the dynamic pressure of the gas flow increases and the static pressure decreases. Due to the low static pressure, it will attract the surrounding air, and at the same time, due to the gas viscosity, it will also carry the surrounding air with it. Further, the mixing process makes the air flow speed decrease and the flow increase during the journey. In order to increase the flow of the ejector flow field, it is necessary to introduce the same direction air flow around the limited space at the same time, so that the gas in the limited space can be given the same flow direction to the greatest extent.

[0055] In one embodiment, the positions of the air outlets 21 of the pair of pipe bodies 20 can be asymmetrically arranged relative to each other. For example, the air outlets 21 are arranged on the same side of the pair of pipe bodies 20, or the air outlets 21 are arranged at different angular positions relative to the respective axes o of the pair of pipe bodies 20.

[0056] In actual use, when the air flow to the film surface is insufficient, the pipe body can be rotated by a certain angle around the axis o, so as to adjust the angle of the air outlet relative to the axis o, so that the track distance of the air flow adhering to the pipe wall is increased, the influence range of the ejector flow field is increased, and the flow of the mixed ambient air is increased, thereby ensuring the air flow to the film surface. In order to realize the angular rotation of the pipe body, the pipe body and the connecting body are angularly connected, for example, the connecting body tightly connects the flanges at the ends of the pipe body, thereby allowing the pipe body to rotate relative to the axis o.

[0057] In one embodiment, the initial flow rate of the air flow blown out of the air outlet 21 can be further increased to increase the strength of the ejector flow field and further increase the air flow to the film surface. For example, the initial flow rate of the air flow blown out of the air outlet 21 can be increased by changing the air guide structure in the static pressure tank, the shape and size of the air outlet 21, etc.

[0058] In one embodiment, the structure is designed according to the expected flow rate when designing the distance between the two tubes. When the distance between the two tubes 21 is too close at the initial flow rate determined by the air outlet 21, the area between the two tubes 21 is too small, resulting in that the air flow blown out of the air outlet 21 can generate a strong injection flow field, but the range of the injection flow field is too small to generate the expected flow rate. When the distance between the two tubes is too far, the area between the two tubes is too large, resulting in that the injection flow field generated by the two tubes on both sides is separated from each other, and the ambient air cannot be accelerated through the injection flow field, and the expected flow rate cannot be generated. Therefore, for each determined initial wind speed of the air outlet 21, there is an optimal tube distance range.

[0059] The main purpose of the embodiments of the present disclosure is to amplify the flow rate of the air outlet through the injection flow field to meet the demand. However, due to the above reasons, the distance between the two tubes is too large or too small at a certain air outlet wind speed, which will reduce the flow rate generated by the injection flow field. At the same time, because the proportion of the flow rate generated by the injection flow field in the final flow rate has an upper limit, for different demand flow rates, the air outlet wind speed is also different, and the optimal tube distance also changes accordingly. Therefore, in order to make the most of the flow rate generated by the injection flow field, it is necessary to determine the optimal tube distance range according to the range of the demand flow rate.

[0060] For example, as shown in FIG. 2, in the second working state, the air outlet 21 is arranged on the outer side of the tube 20 wall at an angle of 45 degrees relative to the axis o; as shown in FIG. 3, in the third working state, the air outlet 21 is arranged on the inner side of the tube 20 wall at an angle of 45 degrees relative to the axis o, so as to obtain different air flow temperature drop loss effects. Figure 4 Figure 5 For example, as shown in FIG. 2, in the second working state, the air outlet 21 is arranged on the outer side of the tube 20 wall at an angle of 45 degrees relative to the axis o; as shown in FIG. 3, in the third working state, the air outlet 21 is arranged on the inner side of the tube 20 wall at an angle of 45 degrees relative to the axis o, so as to obtain different air flow temperature drop loss effects.

[0061] It is found through experiments that the position accuracy of the air flow separating from the tube 20 wall in the static pressure box of the first embodiment of the present disclosure is not easy to control, which can cause the air flow to be unable to fully blow to the film surface. To solve this problem, as shown in FIG. 4, the static pressure box of the second embodiment of the present disclosure is designed as a regular hexagon, and the edges formed by the intersection of the two adjacent edges control the position of the air flow separating from the tube 20 wall. As shown in FIG. 5, when the air flow flows along the outer surface of the tube 20 wall for a distance and the flow rate is reduced to a threshold range close to separation, the air flow will be prompted to separate from the tube 20 wall in advance due to the edge, so the position of the edge can be set to further improve the direction accuracy of the air flow blowing to the film surface. Figures 6-8 Figures 7-8 In the third embodiment of the present disclosure, as shown in FIG. 6, the static pressure box only includes one tube 20, and the air outlet 21 of the one tube 20 can also meet the air blowing amount requirement of the film surface in some cases.

[0062] In the third embodiment of the present disclosure, as shown in FIG. 6, the static pressure box only includes one tube 20, and the air outlet 21 of the one tube 20 can also meet the air blowing amount requirement of the film surface in some cases. Figure 9

[0063] ​​​In one embodiment, there are two pipe bodies 20, which are connected by a gear or linkage mechanism to allow the two pipe bodies to rotate synchronously when adjusting the air outlet angle. This makes the pipe body angle adjustment process more convenient and ensures precise control of the air outlet angle 21 of the two pipe bodies 20.

[0064] In one embodiment, a baffle is provided below the pipe body to ensure that the airflow blown out of the air outlet 21 is fully mixed with the jet airflow, resulting in uniform temperature.

[0065] The velocity field of the airflow from the static pressure box in the second embodiment of this disclosure is simulated, such as... Figure 10 As shown, when the initial airflow velocity from the outlet 21 corresponds to an air pressure of 100 Pa, the airflow can adhere to the outer surface of the pipe body 20, flow along the two positive edges of the cross section, and then exit from the edge; as Figure 11 As shown, when the initial airflow velocity from the outlet 21 corresponds to an air pressure of 500 Pa, the airflow can adhere to the outer surface of the pipe body 20, flow through the three positive edges of the cross section, and then exit from the edge; as Figure 12 As shown, when the initial airflow velocity from the outlet 21 corresponds to an air pressure of 1000 Pa, the airflow can only adhere to the outer surface of the pipe 20 wall, flow through the three positive edges of the cross section, and then exit from the edge. However, some of the airflow has already detached from the pipe 20 wall at the second edge due to excessive flow velocity. As can be seen from the above experiment, when using the embodiment of this disclosure, only within a certain flow velocity range can a larger initial flow velocity increase the flow distance adhering to the outer surface of the pipe 20 wall.

[0066] This disclosure also provides a film stretching device, including a fan chamber, a conveying mechanism, and a static pressure chamber. The fan chamber is powered by a pump and heated by a heating mechanism. The conveying mechanism is, for example, a conveyor belt to convey the film. The static pressure chamber can be a group of multiple static pressure chambers arranged in an array. The film is conveyed from one side to the other side through the group of static pressure chambers, and the surface of the film is gradually heated or cooled during the process.

[0067] In one embodiment, the fan chamber is powered by an impeller or fan, and heating or cooling capacity is provided by a heat exchanger or surface cooler. In another embodiment, the conveying mechanism uses a chain clamp drive system to convey the diaphragm.

[0068] The temperature field during the operation of the film stretching equipment was simulated, such as... Figure 13 As shown, it can effectively control the airflow temperature in a certain area, and at the same time, it can also demonstrate that during operation, it does indeed draw in cold air from the surrounding environment and mix it with the hot air it blows out.

[0069] A smooth simulation was performed on the static pressure box consisting of two tubes 20, such as... Figure 14As shown, the air outlet 21 is arranged at a substantially horizontal position on the side away from the two pipe bodies 20. It can be seen that the air flow blown from the air outlet 21 flows along the outer surface of the pipe body 20 by about 180 degrees, mixes with the ambient air flow in the region between the two pipe bodies 20, and then separates from the pipe body 20 near the hexagonal edge to blow downward in the drawing.

[0070] The embodiments of the present disclosure also provide a method for blowing air flow to the surface of a film, comprising:

[0071] S1, presetting a target flow of air flow blown to the surface of the film; calculating the target flow required to be blown to the surface of the film according to factors such as the size, material and stretching amount of the film.

[0072] S2, adjusting the initial flow rate of the air flow blown from the air outlet and the track distance of the stable flow along the outer surface of the pipe body according to the target flow and the structure size of the pipe body, so as to maximize the proportion of the ambient air flow in the target flow, reduce the initial flow rate of the air outlet, and achieve the purpose of amplifying the flow, wherein the pitch angle of the pipe body is adjusted around the axis to achieve the purpose of adjusting the track distance of the stable flow along the outer surface of the pipe body.

[0073] In one embodiment, the method can further comprise:

[0074] S3, calculating and setting the temperature of the air flow of the air outlet according to the required temperature and the proportion of the mixed ambient air flow, and setting a heat preservation layer on the surface of the pipe body 21 through the track process of the stable flow of the air flow along the pipe body 21, so as to cut off the temperature transfer between the internal environment and the external environment of the pipe body 21 to a certain extent, and have a heat preservation effect on the air flow temperature in the pipe body 21.

[0075] In the description of the embodiments, any reference to direction or position is only for the convenience of description and cannot be understood as any limitation on the protection scope of the present application. The following description of the preferred embodiments will involve combinations of features, which can exist independently or in combination, and the present application is not particularly limited to the preferred embodiments. The scope of the present application is defined by the claims.

[0076] The above is only a preferred embodiment of the present application and cannot be used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A plenum chamber for blowing an air flow introduced from a fan chamber towards a surface to be treated, characterised in that, The utility model relates to a kind of static pressure box, including: Pipe body (20), along the direction of axis (o) direction equisection extends; Connecting body (10), for the pipe body (20) is connected around the axis (o) with the fan chamber, indexable; Wherein, the pipe body (20) wall is formed with the air outlet (21) extending along the direction of axis (o), the opening direction of the air outlet (21) on the section is tangent to the outer surface profile of the wall of the pipe body (20) at the air outlet (21) or is a angle, to adapt to the airflow blown from the air outlet (21) in the section Stable flow of a trajectory that the outer surface of the pipe body (20) wall is attached, and the ambient gas around the trajectory is blown to the surface to be handled together; The number of the pipe body (20) is two, and the pipe body (20) is connected by gear or connecting rod mechanism, so that the two pipe bodies (20) can be rotated synchronously when adjusting the angle of air outlet.

2. The hydrostatic tank of claim 1, wherein, The opening direction of the air outlet (21) on the section is directed away from the surface to be handled.

3. The hydrostatic tank of claim 1, wherein, The number of the pipe body (20) is two, and the two pipe bodies (20) are arranged side by side in the same direction, and the air outlets (21) of the two pipe bodies (20) are symmetrically arranged opposite to each other.

4. The hydrostatic tank of claim 1, wherein, The number of the pipe body (20) is two, and the two pipe bodies (20) are arranged side by side in the same direction, and the air outlets (21) of the two pipe bodies (20) are asymmetrically arranged opposite to each other.

5. The hydrostatic tank of claim 1, wherein, The pipe body section is centrally symmetric with respect to the axis (o).

6. The hydrostatic pad of claim 1, wherein, The section shape of the pipe body (20) is polygonal.

7. A film stretching apparatus characterized by comprising: The utility model relates to a kind of static pressure box, including: Fan chamber, for generating airflow; Conveying mechanism, for conveying film; The static pressure box of any one of claims 1-6 is used to blow the airflow introduced from the fan chamber to the surface of the film conveyed by the conveying mechanism.

8. A method of blowing an air stream against a surface to be treated, using a static pressure box according to any one of claims 1-6, characterized in that, The utility model relates to a kind of static pressure box, including: Pre-set target flow of airflow blown to the surface of film; According to the target flow and pipe body structure size, the initial flow rate of the airflow blown from the air outlet and the trajectory distance of stable flow attached to the outer surface of pipe body wall are adjusted, so that the proportion of ambient airflow in target flow is maximized, to reduce the initial flow rate of air outlet, reach the purpose of amplifying flow, wherein, by adjusting the index angle of the pipe body around the axis, the trajectory distance of stable flow attached to the outer surface of pipe body wall is adjusted.

Images